2-amino-7-chloro-anthraquinone and process of making the same



Patent ed June 16,1931

UNITED STATES PATENT OFFICE IVAN GUBELMANN, HENRY J. WEILAND AND OTLIO ST'ALLMAN'N, OF SOUTH MIL- WAUKEE', VTISCONSIN, ASSIGNORS, BY MESNE ASSIGNMENTS, T NEWPORT CHEMI- GAL CORPORATION, .A CORPORATION OF DEL-AWARE 2-AMINO-7-GI-ILORO-ANTH'RAQUINONE No Drawing. Application filed July 2,

This invention relates to 2-amino-7-chloroanthraquinone and to a process for making the same. I

It is an object of this invention to provide a simple and efficient method for making 2-amino-7-chloro-anthraquinone, which is an intermediate for Valuable dyestuffs.

Other and further important objects of this invention will become apparent from the disclosures in the following description and appended claims.

We have now discovered that 2-nitro-7- chloro-anthraquinone, described and claimed in our co-pending application Serial No. 203,262, filed July 2, 1927 under certain conditions can be reduced to2-amino-7-chloroanthraquinone. It was not to be anticipated that this reduction would run so smoothly,

giving such excellent yields of the reduced product, since this is the first beta-nitroanthraquinone, to the best of our knowledge, which has been reduced successfully.

Our method consists in reducin 2-nitro-7- reduction reaction proceeds practically quan titatively to the desired end product.

This reaction is probably best expressed b the following chemical equation:

2-amino-7-chloro-anthraquinone crystallizes from chloro-benzene in the form of light orange colored needles, which melt at 302 to 303 C. The compound is practically insoluble in cold organic solvents, such as chloro benzene, alcohol and glacial acetic AND PROCESS OF MAKING- THE SAME 1927. Serial No. 203,263.

are suspended in 5000 parts of Water containing 4,0 parts of caustic soda and 625 parts of sodium sulphide (QH O). The mass is heated to the boiling point and boiled for 1 to 2 hours. The product is then filtered off, Washed with hot water and dried. The yield of 2amino-7-chloro-anthraquinone is practically quantitative.

We are aware that numerous details of the process may be varied through a wide range without departing from the principles of this invention, and we therefore, do not pury c o (BU v(ENE, o 0

which may be prepared by reducing 2-nitro- 7-chloro-anthr.aquinone with sodium sulphide at an elevated temperature. In testimony whereof we have hereunto subscribed our names at Oarrollville, Mili waukee County, Wisconsin. I

IVAN GUBELMANN. HENRY J. WEILAND. OTTO STALLMANN. 

